Level select:
Select the number of players with controller one, then hold Down + B on controller two and press Start on controller one.

Hint: Arcade-style control:
You can experience the arcade-style control for the game if you have a four-player adapter for the NES. Player one has controllers one and two while player two has controllers three and four. At the controller position, you turn both controllers together in both hands. Use the D-pad on the left controller to move your character while the D-pad on the right controller makes your character shoot.
Hint: Mode select:
Note: Select these modes by using the D-pad.

One player, one controller. Play in one player mode with one controller.

One player, two controllers. Play in one player mode with two controllers (arcade controls in one player).

Two Players, two controllers. Play in two player mode with two controllers (one for each person).

Two players, four controllers. Play in two player mode with four controllers (arcade controls in two player).